Install available sources with the SDK product

[laeubi]

Currently only some sources are included in the SDK product these are those that explicitly specified in source features. As removing more and more third party dependencies from features, they will also vanish from source features and therefore missing in the SDK product. Beside that, managing source features itself is a tedious task.

This enables the <installSources> option for the SDK product that will install any available source with a bundle automatically.

FYI @merks @iloveeclipse

Fix #1767

[laeubi]

Technically this adds <property name="org.eclipse.update.install.sources" value="true"/> to the profile, that means if one installs additional software into the SDK and the updatesite is using a recent P2/Tycho even these sources will be installed along with the product.

[akurtakov]

Looks very promising. https://download.eclipse.org/eclipse/downloads/drops4/I20240211-1800/buildlogs/reporeports/reports/versionChecks.html (with the correct new Ibuild) is what should be checked to verify what has been added.

[akurtakov]

I'm merging this one as we are getting close to M3 and with the comparator issues on last 2 I-build there would hoepfully be extra I-build today.

[laeubi]

@akurtakov I didn't see this comparator erros in verification builds, so probabbly a compiler change that needs deployment of new compiler as well.